Application of zinc-aluminum spinel in zinc negative electrode of zinc-nickel battery and zinc-nickel battery

Abstract

The invention relates to application of zinc-aluminum spinel in a zinc negative electrode of a zinc-nickel battery and the zinc-nickel battery. The invention relates to an application of zinc-aluminum spinel in a zinc-nickel battery zinc negative electrode. The zinc-aluminum spinel with a ZnAl2O4 structure is used as an active substance or an additive of the zinc negative electrode. The zinc-nickel battery comprises a nickel positive electrode and a zinc negative electrode; wherein the zinc negative electrode adopts zinc-aluminum spinel with a ZnAl2O4 structure as an active substance or an additive. The zinc-aluminum spinel microstructure adopted in the invention is an ultrafine micropore particle, has the characteristics of good fluidity, good alkali resistance, high electrolyte wettability and the like, and has the advantages of high crystallinity, good expansion resistance and the like; according to the applied zinc negative electrode, zinc ions dissolved in electrolyte can be deposited in situ in a microporous structure during charging, so that the possibility of forming dendritic crystals on the surface of the electrode is reduced; the cathode material can be used as a cathode active material of a zinc-nickel battery and can also be used as a cathode additive.

Description

Technical Field

[0001] The present invention relates to the technical field of alkaline secondary battery materials, in particular to the application of zinc aluminate spinel in the zinc negative electrode of zinc-nickel batteries and zinc-nickel batteries. Background Art

[0002] The currently available secondary batteries mainly include lead-acid batteries, nickel-metal hydride batteries, and lithium-ion batteries. Among them, lead-acid batteries have a low specific energy, generally only reaching 30-35 Wh / Kg, with a cycle life of about 300-350 times, requiring a long charging time. At the same time, lead is a toxic heavy metal, and if not properly treated during production and recycling, it will cause serious pollution to the environment, and its production and use have been restricted by countries around the world. Nickel-metal hydride batteries have a low working voltage, large self-discharge at high temperatures, and require a large amount of rare earth raw materials, resulting in a relatively high cost price. Currently, they are only suitable as power sources for small appliances. Lithium-ion batteries have a relatively high specific energy, capable of reaching 80-120 Wh / Kg, allowing for large current charging and discharging, and causing no pollution to the environment during production and use, having advantages such as environmental protection. However, lithium-ion batteries have poor safety performance in high-capacity and high-voltage usage environments, and at the same time face a series of problems such as difficult recycling and pollution of waste lithium-ion batteries, and are restricted in some special application fields. Zinc-nickel batteries do not contain toxic substances such as mercury, cadmium, and lead, are easy to recycle, non-flammable, and non-explosive. Due to their high electrical energy and suitable energy density, they perform excellently at high and low temperatures and have the highest specific energy in the alkaline battery system, and can replace lead-acid batteries, metal hydride batteries, and lithium-ion batteries in many application scenarios.

[0003] Traditional zinc-nickel battery negative electrodes have phenomena such as deformation, dendrite growth, passivation, and corrosion. The reason is that ZnO has a large solubility in KOH solution, and zinc ions are easily dissolved out during the discharge process. During the charging process, zinc ions are deposited on the uneven protruding parts of the electrode surface to form dendrites. The dendrites penetrate the separator, causing a short circuit between the positive and negative electrodes and resulting in battery failure. Although there have been great improvements in current technologies, the problems of expansion, shedding, and dendrite growth of the zinc negative electrode material of zinc-nickel batteries cannot be effectively solved. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides the application of zinc aluminate spinel in the zinc negative electrode of zinc-nickel batteries and zinc-nickel batteries. Zinc aluminate spinel with a ZnAl 2 O 4 structure is used as the active substance or additive of the zinc negative electrode material of zinc-nickel batteries. This material has high crystallinity and certain mesoporous properties. Compared with an electrode simply mixed with zinc oxide and additives, it can inhibit the expansion and shedding of the zinc negative electrode of zinc-nickel batteries and reduce dendrite growth.

[0005] The technical solution adopted by the present invention to solve its technical problems is: the application of zinc aluminate spinel in the zinc negative electrode of zinc-nickel batteries, using ZnAl 2O 4 The zinc-aluminum spinel of the structure is used as an active material or an additive for the zinc negative electrode.

[0006] Furthermore, ZnAl 2 O 4 The zinc-aluminum spinel of the structure is prepared according to the following steps:

[0007] I. After mixing a zinc source and an aluminum source, an alkali solution is added for reaction to obtain a precursor.

[0008] II. The precursor obtained in step I is calcined at 650 - 950 °C for 2 - 10 h to obtain the zinc-aluminum spinel of the ZnAl 2 O 4 structure;

[0009] Among them, the zinc source is a zinc salt solution or an oxide of zinc; the aluminum source is an aluminum salt solution, an oxide of aluminum or a hydroxide of aluminum; the molar ratio of zinc in the zinc source to aluminum in the aluminum source is 1:2.

[0010] Furthermore, the zinc salt solution is an aqueous zinc salt solution obtained by dissolving a water-soluble zinc salt in water; among them, the water-soluble zinc salt is one or a combination of two or more of zinc sulfate, zinc chloride and zinc nitrate; the oxide of zinc is ZnO.

[0011] Furthermore, the aluminum salt solution is an aqueous aluminum salt solution obtained by dissolving a water-soluble aluminum salt in water; among them, the water-soluble aluminum salt solution is one or a combination of two or more of aluminum sulfate, aluminum chloride and aluminum nitrate; the oxide of aluminum is Al 2 O 3 ; the hydroxide of aluminum is Al(OH) 3 .

[0012] Furthermore, step I is specifically: After mixing the solution after dissolving zinc sulfate with Al 2 O 3 or Al(OH) 3 powder, under the condition of stirring, pour it into an aqueous NaOH solution, and the generated precipitate is filtered, washed and dried to obtain the precursor.

[0013] Furthermore, step I is specifically: After mixing the solution after dissolving aluminum sulfate with ZnO powder, under the condition of stirring, pour it into an aqueous NaOH solution, and the generated precipitate is filtered, washed and dried to obtain the precursor.

[0014] Furthermore, step I is specifically: After mixing the aqueous solution after dissolving zinc sulfate with the aqueous solution after dissolving aluminum sulfate, under the condition of stirring, pour it into an aqueous NaOH solution, and the generated precipitate is filtered, washed and dried to obtain the precursor.

[0015] Further, step two specifically is: calcining the precursor obtained in step one at 700 °C for 5 h to obtain zinc aluminate spinel with a ZnAl 2 O 4 structure.

[0016] The zinc-nickel battery includes a nickel positive electrode and a zinc negative electrode; wherein, the zinc negative electrode uses the above-mentioned zinc aluminate spinel with a ZnAl 2 O 4 structure as an active material or an additive.

[0017] Further, the preparation method of the zinc negative electrode is: after pulverizing and sieving the zinc aluminate spinel with a ZnAl 2 O 4 structure, then mixing the slurry and coating it on a metal substrate to obtain the zinc negative electrode.

[0018] Advantages of the present invention: The zinc aluminate spinel adopted in the present invention has a microstructure of ultra-fine microporous particles, and has the characteristics of good fluidity, good alkali resistance, high electrolyte wettability, etc., and has the advantages of high crystallinity and good anti-swelling property; for the applied zinc negative electrode, the zinc ions dissolved in the electrolyte during charging can be deposited in-situ in the microporous structure, reducing the possibility of forming dendrites on the electrode surface; it can be used as the negative electrode active material of the zinc-nickel battery or as a negative electrode additive. Description of the Drawings

[0019] Figure 1 XRD pattern of the zinc aluminate spinel with a ZnAl 2 O 4 structure for Example 3;

[0020] Figure 2 Discharge curve of the zinc-nickel battery for Example 4. Specific Embodiments

[0021] To deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with the drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0022] Example 1

[0023] Mix an aqueous zinc sulfate solution and aluminum hydroxide powder in a molar ratio of Zn:Al of 1:2. Under the conditions of 70 °C and stirring, pour an aqueous sodium hydroxide solution into the mixed solution and maintain the pH value of the mixed system at 8-9. After fully reacting for 2 h, naturally cool and age for 6 h to room temperature. Filter, wash the precipitate, dry it at 100 °C, and pulverize it to obtain a precursor; then sinter the precursor at 700 °C for 5 h to obtain zinc aluminate spinel with a ZnAl 2 O 4 structure.

[0024] Example 2

[0025] Mix an aqueous aluminum sulfate solution and zinc oxide powder in a ratio of the amount of substance Zn:Al of 1:2. Under the conditions of 70 °C and stirring, pour the aqueous sodium hydroxide solution into the mixed solution, and maintain the pH value of the mixed system at 8 - 9. After fully reacting for 2 h, naturally cool and age for 6 h to room temperature. Filter, wash the precipitate, dry it at 100 °C, and pulverize it to obtain a precursor; then sinter the precursor at 700 °C for 5 h to obtain ZnAl 2 O 4 structured zinc aluminate spinel.

[0026] Example 3

[0027] Mix an aqueous aluminum sulfate solution and an aqueous zinc sulfate solution in a ratio of the amount of substance Zn:Al of 1:2. Under the conditions of 70 °C and stirring, pour the aqueous sodium hydroxide solution into the mixed solution, and maintain the pH value of the mixed system at 8 - 9. After fully reacting for 2 h, naturally cool and age for 6 h to room temperature. Filter, wash the precipitate, dry it at 100 °C, and pulverize it to obtain a precursor; then sinter the precursor at 700 °C for 5 h to obtain ZnAl 2 O 4 structured zinc aluminate spinel.

[0028] For the ZnAl 2 O 4 structured zinc aluminate spinel of Example 3, perform XRD detection, and its pattern is as Figure 1 shown.

[0029] Example 4

[0030] After pulverizing and sieving the zinc aluminate spinel material obtained in Example 3, take 90 parts of the zinc aluminate spinel material, 2 parts of HPMC glue (hydroxypropyl methylcellulose), 3 parts of SBR (styrene-butadiene rubber), and 5 parts of conductive agent by mass, mix and stir to form a slurry, coat it on a copper substrate to form an electrode, and after rolling, slicing, and spot-welding the electrode tabs, cooperate with a finished nickel oxide electrode to form a zinc-nickel battery system.

[0031] Perform charge and discharge tests on the zinc-nickel battery system of Example 4 in a 6 M KOH solution, and its discharge curve diagram is as Figure 2 shown.

[0032] In the present invention, ZnAl 2 O 4The zinc-aluminum spinel of the structure has high crystallinity, certain mesoporous properties, is ultra-fine pore granular, has characteristics such as good fluidity, good alkali resistance and high electrolyte wettability, and has advantages such as high crystallinity and good anti-swelling property; its microporous structure provides sites for zinc ion deposition, can effectively reduce the formation of dendrites on the electrode surface, solves or partially solves problems such as swelling, shedding and dendrite growth of the zinc negative electrode material of the zinc-nickel battery; and prolongs the service life of the zinc-nickel battery.

[0033] The above embodiments should not limit the present invention in any way, and all technical solutions obtained by means of equivalent replacement or equivalent conversion fall within the protection scope of the present invention.

Claims

1. Application of zinc-aluminum spinel in zinc negative electrode of zinc-nickel battery, characterized by: Zinc aluminum spinel with a ZnAl2O4 structure is used as an active material or additive for a zinc negative electrode.

2. The use of the zinc-aluminum spinel in the zinc negative electrode of a zinc-nickel battery according to claim 1, characterized in that: The zinc-aluminum spinel with ZnAl2O4 structure is prepared according to the following steps:

1. Mix the zinc source and the aluminum source, then add an alkaline solution to react to obtain a precursor; 2. calcining the precursor obtained in step 1 at 650-950°C for 2-10h to obtain zinc-aluminum spinel with ZnAl2O4 structure; The zinc source is a zinc salt solution or zinc oxide; the aluminum source is an aluminum salt solution or aluminum oxide or hydroxide; and the ratio of the amount of zinc in the zinc source to the amount of aluminum in the aluminum source is 1:

2.

3. The use of the zinc-aluminum spinel in the zinc negative electrode of a zinc-nickel battery according to claim 2, characterized in that: The zinc salt solution is a zinc salt aqueous solution obtained by dissolving a water-soluble zinc salt in water; wherein the water-soluble zinc salt is one or a combination of two or more of zinc sulfate, zinc chloride and zinc nitrate in any proportion; and the zinc oxide is ZnO.

4. The use of the zinc-aluminum spinel in the zinc negative electrode of a zinc-nickel battery according to claim 3, characterized in that: The aluminum salt solution is an aluminum salt aqueous solution obtained by dissolving a water-soluble aluminum salt in water; wherein the water-soluble aluminum salt solution is a combination of one or more of aluminum sulfate, aluminum chloride and aluminum nitrate in any proportion; the aluminum oxide is Al2O3; and the aluminum hydroxide is Al(OH)3.

5. The use of the zinc-aluminum spinel in the zinc negative electrode of a zinc-nickel battery according to claim 4, characterized in that: Step 1 is specifically as follows: after mixing the solution of dissolved zinc sulfate with Al2O3 or Al(OH)3 powder, pouring into the NaOH aqueous solution under stirring, filtering, washing and drying the produced precipitate to obtain a precursor.

6. The use of the zinc-aluminum spinel in the zinc negative electrode of a zinc-nickel battery according to claim 4, characterized in that: Step 1 is specifically as follows: after mixing the solution of aluminum sulfate with ZnO powder, pouring NaOH aqueous solution into the mixture under stirring, filtering, washing and drying the generated precipitate to obtain a precursor.

7. The use of the zinc-aluminum spinel in the zinc negative electrode of a zinc-nickel battery according to claim 4, characterized in that: Step 1 is specifically as follows: after mixing the aqueous solution of zinc sulfate and the aqueous solution of aluminum sulfate, pouring the aqueous solution of NaOH into the solution under stirring, filtering, washing and drying the generated precipitate to obtain a precursor.

8. The use of the zinc-aluminum spinel according to any one of claims 2 to 7 in the zinc negative electrode of a zinc-nickel battery, characterized in that: The specific step 2 is: calcining the precursor obtained in step 1 at 700° C. for 5 hours to obtain zinc aluminum spinel with a ZnAl2O4 structure.

9. Zinc-nickel battery, characterized in that: It comprises a nickel positive electrode and a zinc negative electrode; wherein the zinc negative electrode adopts the zinc aluminum spinel with ZnAl2O4 structure in the application of any one of the zinc aluminum spinels in claims 2-8 in the zinc negative electrode of zinc-nickel battery as an active material or additive.

10. The zinc-nickel battery according to claim 9, characterized in that: The zinc negative electrode is prepared by the following method: zinc aluminum spinel with ZnAl2O4 structure is crushed and sieved, and then slurried and coated on a metal substrate to obtain a zinc negative electrode.

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